EP-A 1 763 066 discloses a lamp with a base at one end which is constructed from three bulbs. It describes as key parameters an outer diameter of the outer bulb of a maximum of 25 mm and, as a minimum value, a value which is based on the power of the lamp. Furthermore, said document finds a minimum value of 9 mm for the outer diameter of the inner bulb and a ratio between A and B of at least 1.14 to be essential for low-wattage lamps with a power of between 20 and 130 W.